"We consider these demands are against international law," Erdogan told journalists after Eid al-Fitr prayers in Istanbul. "It is a breach of Qatar's sovereignty rights."
Qatar said early Saturday it received the list of demands to be met to end a blockade against the Gulf state but they were "not reasonable" and "actionable".
The demands include the closure of Al Jazeera television network, downgrading ties with Iran and extraditing "terrorists", according to reports.
The four countries have given Doha a 10-day deadline to meet the demands.
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